1. Field of Invention
This invention relates generally to a process for recovery of low-level heat in steam reforming plants, or other systems and more specifically concerns effecting such heat recovery by saturating a hydrocarbon feed stock with process condensate.
2. Description of the Prior Art
The commercial application of steam reforming for the production of hydrogen, ammonia, methanol, and other products involves the catalytic reaction of a hydrocarbon feedstock with steam to form a mixture of hydrogen, carbon monoxide, carbon dioxide, water vapor, and residual hydrocarbons. Steam for this "reforming" reaction has typically been supplied from boilers utilizing treated boiler feedwater. The mixture of gases produce by the catalytic reaction are treated in various downstream processes which include cooling in which the water vapor condenses and is separated from the gas stream. This condensed water vapor is the "process condensate" which is typically contaminated with carbon dioxide and sometimes other compounds such as methanol and ammonia which are formed in the processes downstream of the catalytic reforming reaction. This condensate has typically been sent to a purifying system or "stripper" to remove the carbon dioxide and other contaminants, after which it is re-used as feed water to the plant boilers.
Recent technology has incorporated systems in which the process condensate is heated and sprayed into a packed tower or other vessel to saturate the hydrocarbon gas feedstock to the plant. This type of system can recover low level heat only to the extent allowed by liquid phase heating of the process condensate, and a temperature difference must exist both between the heat source and the condensate liquid and between the condensate liquid and the hydrocarbon gas feedstock.